Listed for many years as the Model SO, the Deckel tool & Cutter grinder has been widely cloned (many examples are now made in China). In the UK the best-known copy was by Alexander, who produced a version to the same very high standard of the original - as well as a simplified version advertised as intended mainly for sharpening the D-bit cutters of the firm's well-known engraving machines. For many years the ordinary Alexander model was listed simply as the "Universal", sometimes with the Model Type stamped into the maker's plate as the UX - this appearing to indicate a machine without the extra-cost diamond wheel dresser built into the wheel guard. The machine could be had as a self-contained bench model, with a built-on motor, or with the complete 1/4 h.p. motor and drive system was safely enclosed inside a steel cabinet stand. A later model of Alexander was the 2CG, this also being available in bench and cabinet styles and fitted with interchangeable spindle flanges to simply wheel changing and the ability to accept cutters up to 5/8" (16 mm) in diameter. Many Alexander tool and cutter grinders are marked as manufactured by Precision Grinding Ltd. of Precision Works, Mill Green Road, Mitcham Junction in Surrey, this being a Subsidiary of George H. Alexander of Birmingham.
Taking a grinding wheel 4" in diameter by 2" wide with a 25/32" bore, the Deckel/Alexander SO was fitted with a 3-phase, 0.25 hp, 2800 rpm motor with the wheel running at around 4500 r.p.m. The cutter to be sharpened was secured in, on early models, an unknown type of collet with a 16 mm shank that had a maximum capacity of 1/2" (12 mm). Later (and by far the more common type) used what the makers listed as a Schaublin Type 20 with a 5/8" capacity (17 mm). Hence, as the early collets are now unobtainable (though they can be specially made), before buying one of these machines (or ordering new collets) do check what the situation is, An early model without a complete set of collets, or with ones that are worn, will be very expensive to rectify - and should be far cheaper to buy than one fully equipped. A further problem arises with regard to the later collets sold around the world as the Type U2 and often listed as being: "suitable for Alexander and Deckel grinders". Owners report that these fit the Alexander version, but not the Deckel - or the threads, at least, are different. If you have direct experience of this situation and any difficulties it has caused, the writer would be pleased to hear from you.**
Collets were mounted in a housing (the index carrier) on top of a short-travel slide fitted with a vernier scale. The slide was fastened to the end of a swan-necked arm, mounted on a double-swivel base which itself was carried on a boss that could be slid along and rotated around a horizontal bar. In addition, the bar was finely adjustable "left and right" by a micrometer screw with its dial and handwheel on the left-hand face of the machine.
In the 1970s Deckel introduced the Model S0E (to run alongside the S0) an improved design but one that was operated in exactly the same way. Besides modern, sleeker line, modifications included: a built-in motor with an adjustable dust exhaust hood (it could be repositioned to allow wheel dressing); more complete guarding of the wheel; an axially moveable wheel spindle (under the control of a micrometer dial) that allowed precise wheel dressing and a telescopic, stub-mounted horizontal support bar - an arrangement which, with the removal of the end-support bracket, afforded much greater clearance around the job.
One option available for the SOE was a bolt-on Optical Measuring Projector. This enabled the operator to view the profile of a cutter mounted in the holder and assess, from a scale, the various dimensions and angles. The unit consisted of a housing to hold the optical system and a ground glass reticule on which rested a second reticule that could be rotated through 90°. The measuring projector could only be used on the index head carrier for which it was supplied - the image plane of the ground glass being adjusted so that the axis of the reticule coincided with the tilting axis of the index head and the distance from the object plane corresponded correctly to the magnification ratio.
**A reader writes:
I purchased an early Alexander cutter grinder with only 1 collet, 5/16'', about 2 years ago, not knowing anything about the collet situation. I then brought a U2 type collet, which didn't fit!
I have been using the grinder quite a bit mostly making rotary broaches, sharpening the ends of endmills, etc. Then at the end of December last year I visited Home and Workshop machinery in Sidcup and found a bag of unknown collets that matched my 5/16" exactly (always carried the collet in the hope of finding some!) but the thread was smaller in diameter, the original collet thread is the same dia as the main shaft of the collet. However, the thread pitch 1.2mm was identical (but 1 read on).
Was so happy to of found some collets, cheap as well (£20 for 5!) the thread was no problem, I just made a new draw nut, this did require playing about with the input gears the cut a metric thread on a gearbox super 7.
All good but there is one collet in the 5 which I believe has an imperial pitch thread that is so close to 1.2mm its not noticeable until its tried to be screwed in to my draw nut, which fits all other collets fine.
So, the original collet that came with the machine have no markings at all, nor does the one that has the odd thread (6mm), and a 3/16'', then there is a 1/8'' with "made in Germany" down the shank. (I recognise this which I'll come on to later). A 1/16'' with Schaublin logo on the front. Then finally a 3/8'' Hardinge with what appears to be 2 L's next to each other.
Now, I don't have any proof of this but you might be able to dig up a bit more but I have seen a Steddall lathe (a copy of a Lorch) with a collection of collets that had the same basic dimensions as the collets I sourced. If this is any help but don't take my word for it!